Flexible Manufacturing System Questions and Answers – AC Motors

This set of Flexible Manufacturing System Multiple Choice Questions & Answers (MCQs) focuses on “AC Motors”.

1. Which of the following must be used to convert alternating current to direct current?
a) Rectifier
b) Electric Motor
c) Transformer
d) Generator
View Answer

Answer: a
Explanation: The device which converts alternating current into direct current is known as rectifier. Electric Motor, Transformer and Generator were not used to convert alternating current into direct current.

2. Which motors operate by generating a rotating magnetic field inside the stator?
a) Modular Motors
b) AC Motors
c) DC Motors
d) Rotomotors
View Answer

Answer: b
Explanation: The type of motor which operate by generating a rotating magnetic field inside the stator is known as AC motor. This motor functions with the supply of alternating current.

3. Which of the following does the rotational speed of the motor depends on?
a) Mass
b) Frequency
c) Force
d) Velocity
View Answer

Answer: d
Explanation: The rotational speed of the motor depends on the frequency of the input alternating current signal. Depending on the speed of the rotating magnetic field, the rotor is forced to turn.
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4. Synchronous motors start by themselves.
a) False
b) True
View Answer

Answer: a
Explanation: Synchronous motors cannot start by its own. It requires an external device to initiate its operation. Starter motors or some external exciters were typically used along with synchronous motor to initiate the motor.

5. Which is a device used to initiate the rotation of the rotor when the power is supplied to the synchronous motor?
a) Polarizer
b) Repulser
c) Divider
d) Exciter
View Answer

Answer: d
Explanation: The device which is used to initiate the rotation of the rotor when the power is supplied to the synchronous motor is known as exciter. Electric motor can also be an exciter.

6. Which of the following motors are the most widely used because of its relatively simple construction and low manufacturing cost?
a) Reversible Motor
b) Induction Motor
c) Modular Motor
d) Synchronous Motor
View Answer

Answer: b
Explanation: The motors which are the most widely used because of its relatively simple construction and low manufacturing cost are known as induction motors. In this type, magnetic field is induced in the rotor from the stator.

7. Which of the following motor uses solid state circuitry to replace brushes and Commutator components?
a) Brushless DC Motor
b) Brushless AC Motor
c) Brushed DC Motor
d) Brushed AC Motor
View Answer

Answer: a
Explanation: The motor which uses solid state circuitry to replace the brushes and Commutator components is known as brushless DC Motor. Since the brush is eliminated, inertia is partially reduced resulting in high speed operations.
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8. Which of the following motor uses feedback loop to regulate speed?
a) Modular Motor
b) AC Motor
c) Servomotor
d) DC Motor
View Answer

Answer: c
Explanation: The type of motor which uses feedback loop to regulate speed is known as servomotor. Feedback is the process of sending signal to the system from the existing process to further optimize it.

9. Which consists of copper wire windings around a ferrous metal core?
a) Armature
b) Brush
c) Encoder
d) Regulator
View Answer

Answer: a
Explanation: The component of an electric motor which consists of copper wire windings around a ferrous metal core is known as armature. Input Current will be given to the armature through the Commutator.
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10. Which curve shows the motor torque relationship with angular velocity?
a) Stress Torque curve
b) Stress strain curve
c) Force Torque curve
d) Torque speed curve
View Answer

Answer: d
Explanation: The plot which shows the motor torque relationship with angular velocity is known as torque speed curve. Stress Torque curve, Stress strain curve and Force Torque curve were not used in determining the relationship between motor torque and angular velocity.

11. Which point does the torque required by the motor and the torque required by the load will be balanced in a steady state operation?
a) Modulating Point
b) Operating point
c) Null Point
d) Reduction Point
View Answer

Answer: b
Explanation: The point at which the torque required by the motor and the torque required by the load will be balanced in a steady state operation is termed as Operating point. Modulating Point, Null Point and Reduction Point do not shoe the torque required by the motor and the torque required by the load will be balanced in a steady state operation.

12. DC Servomotors generate low torque at the zero velocity.
a) False
b) True
View Answer

Answer: a
Explanation: DC Servomotors have the ability generate very high torque even at the zero starting velocity. These motors have separate direct current source for field winding and armature winding as power transmitting medium.

Sanfoundry Global Education & Learning Series – Flexible Manufacturing System.

To practice all areas of Flexible Manufacturing System, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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